Medical device having a valve for autoclavability

ABSTRACT

A medical device with a valve for autoclavability is disclosed. The medical device may include a cavity. A channel connects the cavity to an autoclave environment. The channel has a distal end and proximal end. The distal end of the channel may open to the autoclave environment and the proximal end may open to the cavity. A valve may be positioned in or near the channel. The valve may permit gas to flow from the cavity when a pressure inside the cavity is greater than a pressure in the autoclave environment outside the cavity. The valve may also prevent gas from flowing into the cavity when the pressure in the autoclave environment outside the cavity is greater than the pressure inside the cavity.

BACKGROUND Field

The present disclosure relates to sealing medical devices, andparticularly dental devices, during an autoclave procedure.

Technical Background

An autoclave is a common device in medical and dental offices. Theautoclave sterilizes medical and dental instruments using extremetemperatures and pressures to kill bacteria, viruses, fungi, spores, andother contaminants. The temperatures and pressures may vary throughoutthe autoclave procedure. For example, at the beginning of the autoclaveprocess, the temperature in the autoclave may rise to in excess of 110degrees Celsius while removing air from the chamber. Typically,pressurized saturated steam at 121° C. (250° F.) is applied in thechamber for around 15-20 minutes depending on the size of the load andthe contents. At the end of the autoclave process, the temperature andpressure in the autoclave may be restored to approximately thetemperature and pressure of the environment of the autoclave (forexample, on the counter of a dentist's office). Instruments may beremoved from the autoclave chamber before fully cooling off, thussettling of the autoclave process may occur outside the chamber.

Air removal may be accomplished in a variety of ways. Gravitydisplacement autoclaves, also called gravity autoclaves, inject steaminto the autoclave chamber and then rely on that steam, which is heavierthan air, to force the air to leave the chamber through the drain ventat the bottom. Prevacuum or prevac autoclaves use a vacuum pump toremove air from the chamber before steam is admitted to it, which meansthat steam penetrates even porous objects almost instantly.

One instrument that is often autoclaved is an intraoral mirror.Intraoral mirrors, also known as mouth mirrors or dental mirrors, areamong the most functional and frequently used of dental instruments.Viewing objects in a mouth directly is difficult due to a limited, orperhaps nonexistent, line of sight. Intraoral mirrors allow a healthcare provider (HCP), for example dentist, hygienist and others, toindirectly view teeth and other objects in a patient's mouth, such asthe patient's gums and tongue, by observing their reflections in amirror. Health care providers use the intraoral mirror for a variety oftasks, including, but not limited to, evaluation and diagnosis,treatment selection, and even to assist the treatment itself. A healthcare provider may use other tools, such as a dental hand piece, inconjunction with the mirror to conduct procedures, such as toothpreparation, when the procedures are conducted in areas that are notdirectly visible.

Not only are they used as a visual aid, intraoral mirrors are also usedas rigid tools to manipulate or protect objects in a patient's mouth.For example, a health care provider may use an intraoral mirror to shifta patient's cheek to make space for treatment or to expand the mouthspace for improved visibility. In addition, an intraoral mirror canprotect soft and hard tissue structures of a patient's mouth while otherparts of the mouth are treated.

Since an intraoral mirror is in contact with a patient's tissues insidetheir mouth, the mirror must be sterilized before each treatment. Mostintraoral mirrors are made almost entirely of glass and metal. So, theycan withstand the autoclaving process. Only after manyuse-and-sterilization cycles does the mirror eventually lose some of itsclarity and its reflectiveness, thus needing replacement.

Dental mirrors may exist that have electronic components such as acamera and light emitting diode (LED) lights connected through a printedcircuit board (PCB). One such dental mirror is described in U.S. Pat.No. 9,655,504, incorporated by reference herein. Electronic componentsmay be sensitive to temperature and particularly moisture. If watercondenses on a PCB, it can cause the PCB to short circuit. Opticalcomponents can also become damaged if exposed to too much heat,pressure, or moisture. For these reasons, these mirrors are often notautoclaved, instead needing other methods of sterilization, such assubmerging in disinfectant liquid or covering with a single-usedisposable sleeve.

Additionally, while medical devices are typically sealed where portionsare joined, these seals may contribute to issues during the autoclaveprocess. Specifically, while airtight seals may prevent air, liquid, andvapors from entering the sealed cavity, it also prevents gas fromescaping from the cavity. This creates a small air pocket. This smallair pocket can cause damage to the medical device as the pressureoutside the medical device changes. For example, if the pressure in theair pocket of a medical instrument becomes substantially larger than thepressure in the cavity, it may force components to detach from theinstrument or may cause components inside to collapse if they cannotsustain the pressure. An air pocket in an airtight sealed cavity has asignificant probability that its pressure will rise substantially whilethe autoclave chamber rises in temperature.

What is needed is an effective device that is sealed to gas,withstanding substantial pressure despite having an air pocket, whilelimiting the rise in the pressure of the air pocket in a controlledmanner.

SUMMARY

There is a need for a low cost, effective element that seals whilepreventing damaging pressure from building in portions of a medical ordental instrument.

According to some embodiments, a medical device includes a cavity. Achannel may be formed in the medical device between the cavity and anautoclave environment. The autoclave environment may be, for example,the interior of an autoclave device, specifically, while the autoclavedevice is in operation. The channel may have a proximal end that opensto the cavity and a distal end that opens to the environment. A valvemay be fluidly connected to the channel and may be capable of sealingthe channel. The valve permits gas to flow from the cavity of the dentalinstrument when a pressure inside the cavity is greater than a pressurein the autoclave environment outside the cavity. The valve may preventgas from flowing into the cavity when the pressure in the autoclaveenvironment outside the cavity is greater than the pressure inside thecavity.

In some embodiments, the valve includes a piston rod that extends intothe channel. A sealing member may be connected to the piston rod. Thespring may bias the piston rod in the proximal direction.

In some embodiments, the medical device includes a printed circuitboard. The printed circuit board may be disposed in the cavity. Thecavity may also include an image sensor operatively coupled to theprinted circuit board. The image sensor may also be inside the cavity.In some embodiments, a light source is operatively coupled to theprinted circuit board. The light source may be inside the cavity.

An indicator may also be included. The indicator may be configured toindicate a pressure difference between a pressure in the environment anda pressure in the cavity. In this sense, the environment may beconsidered more broadly than just the environment of the autoclave. Forexample, the environment may be outside the autoclave—such as a medicalor dental office generally. The indicator may be coupled to the sealingmember. In some embodiments, the indicator indicates a pressuredifference between the pressure in the environment and the pressure inthe cavity by being located at one of a first and a second position.

According to some embodiments, a dental instrument has a channel havinga distal and a proximal end. The proximal end is configured to engage acavity of the dental instrument. A release plug may be located in thechannel. The release plug may include a sealing member coupled to apiston rod. The piston rod is biased in the proximal direction by aspring. The release plug permits gas to flow from the cavity of thedental instrument when a pressure outside the dental instrumentdecreases below the pressure of the air pocket or equivalently thepressure of the air pocket increases above the pressure outside duringthe autoclave process. The release plug also prevents gas from flowinginto the cavity of the dental instrument when the outside pressureincreases above the pressure of the air pocket or equivalently thepressure of the air pocket decreases below the pressure outside duringthe autoclave process.

According to some embodiments, a plug may be for use with a dentalinstrument during an autoclave procedure. The plug may include a hollowhousing having a distal and a proximal end. The proximal end may beconfigured to engage a cavity of the dental instrument. A release plugmay be located in the hollow housing. The release plug may also behollow. The release plug may include a valve. The valve may operate soas to permit gas to flow from the cavity of the dental instrument when apressure outside the cavity decreases relative to the pressure insidethe cavity. The valve may also operate so as to prevent gas from flowinginto the cavity of the dental instrument when the pressure outsideincreases relative to the pressure inside the cavity. The valve mayinclude a piston rod with a sealing member and may be partially withinthe hollow portion of the release plug. The piston rod may be coupled toa spring, which may bias the rod in the proximal direction.

The plug may include an indicator. The indicator may be configured toindicate a pressure difference between the pressure outside and apressure inside the cavity. For example, the indicator may be in a firstposition when there is no or little pressure difference between insidethe cavity and outside. The indicator may be in a second position whenthere is a pressure difference between inside the cavity and outside. Insome embodiments, the first position may be more distal from the secondposition. This may make the first position more visible in the hollowrelease plug. The indicator may be coupled to or formed on the sealingmember.

In some embodiments, a plug may include a hollow cylindrical housinghaving an outer surface, an inner surface, a proximal end, and a distalend. A gasket may be positioned in a groove formed on the outer surfaceof the housing. The gasket may aid in sealing the cavity. An end piecemay be coupled to the distal end of the housing. The end piece may havea void that is aligned with the hollow portion of the housing. A releaseplug may be mated with the inner surface of the hollow portion of thehousing. The release plug may include a hollow cylindrical body having aproximal end and a distal end. A first and a second location may beidentified along the axis of the hollow portion of the release plug. Thefirst location may be distal to the second location. A piston rod may belocated and move axially through a portion of the hollow cylindricalbody.

A spring may be located around the piston rod. The spring may apply aspring force to the piston rod in the proximal direction. A sealingmember may be coupled to the distal end of the piston rod, interior ofthe hollow cylindrical body. The sealing member permits gas to flow fromthe cavity of the dental instrument when a pressure inside the cavity isgreater than a pressure in the environment outside the cavity. Thesealing member may prevent gas from flowing into the cavity when thepressure in the environment outside the cavity is greater than thepressure inside the cavity.

An interior of the hollow portion of the housing may have more than onesection. For example, the hollow portion of the housing may have a firstsection, a second section, and a third section. Each of the sections mayhave a different diameter to accommodate different components. Forexample, the third section may have a diameter that is greater than thediameter of the second section, and the second section may have adiameter that is greater than the diameter of the first section. Thefirst section may be distal to the second section, which may be distalto the third section. In some embodiments, a second gasket may bepositioned in a second groove formed on the outer surface of thehousing. This second gasket may further seal the cavity of a medical ordental instrument. The release plug may also include a release gasketthat helps to seal the release plug in the hollow portion of thehousing.

An indicator may be located on the distal end of the sealing member.When a distal pressure is greater than a proximal pressure, the sealingmember may be proximally displaced. The release plug may be mated to thehousing with a threaded connection.

According to some embodiments, a medical device may include a cavity. Achannel having a sealing member may connect the cavity and anenvironment outside the cavity. The sealing member permits gas to flowfrom the cavity of the medical device when a pressure inside the cavityis greater than a pressure in the environment outside the cavity. Thesealing member may prevent gas from flowing into the cavity when thepressure in the environment outside the cavity is greater than thepressure inside the cavity.

According to some embodiments, the sealing member may be a one-wayvalve. In some embodiments the medical device may be an intra-oralmirror. The medical device may also comprise an image sensor locatedinside the cavity. The image sensor may be operatively connected to aconnector. The connector may be configured to receive a streamer. Thestreamer may be a removable component that is not able to be autoclaved.

According to some embodiments, a medical device includes a cavity. Achannel may be formed in the medical device between the cavity and anenvironment. The environment may be, for example, an autoclave device.The channel may have a proximal end that opens to the cavity and adistal end that opens to the environment. A first and a second locationmay be defined along an axis of the channel. The first location may bedistal to the second location. A piston rod may extend into the cavity.A sealing member may be connected to the piston rod interior of thechannel. A spring biases the piston rod in the proximal direction. Theforce provided by the spring is sufficient to hold the sealing member atthe second location as long as the pressure inside the cavity is notgreater than the pressure of the environment, with an addition of athreshold.

According to some embodiments, when the sealing member is at the firstlocation, the sealing member permits the flow of air through thechannel. And, when the sealing member is at the second location, thesealing member prohibits the flow of air through the channel. Additionalfeatures and advantages of the processes and systems described hereinwill be set forth in the detailed description which follows, and, inpart, will be readily apparent to those skilled in the art from thatdescription or recognized by practicing the embodiments describedherein, including the detailed description which follows, the claims, aswell as the appended drawings.

It is to be understood that both the foregoing general description andthe following detailed description describe various embodiments and areintended to provide an overview or framework for understanding thenature and character of the claimed subject matter. The accompanyingdrawings are included to provide a further understanding of the variousembodiments, and are incorporated into and constitute a part of thisspecification. The drawings illustrate the various embodiments describedherein, and together with the description serve to explain theprinciples and operations of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments set forth in the drawings are illustrative and exemplaryin nature and not intended to limit the subject matter defined by theclaims. The following detailed description of the illustrativeembodiments can be understood when read in conjunction with thefollowing drawings.

FIG. 1 is a diagram illustrating components of a plug with a valve and adental mirror.

FIG. 2 is a diagram illustrating the plug.

FIG. 3 is another diagram illustrating the plug.

FIG. 4 is a cross section view of the plug of FIG. 3.

FIG. 5 is a diagram of a release plug.

FIGS. 6A-6C are a schematic illustrating the operation of the plugaccording to some embodiments.

FIG. 7 illustrates a breakout diagram showing a head portion of a dentalmirror.

FIG. 8 illustrates a perspective diagram of a shell for a head portionof a dental mirror.

FIG. 9 illustrates a streamer portion of a dental mirror.

FIG. 10 illustrates the streamer portion with an outer shell removed.

FIG. 11 illustrates a block diagram of a smart dental mirror.

The features and advantages of the present invention will become moreapparent from the detailed description set forth below when taken inconjunction with the drawings, in which like reference charactersidentify corresponding elements throughout. In the drawings, likereference numbers generally indicate identical, functionally similar,and/or structurally similar elements. Additionally, generally, theleft-most digit(s) of a reference number identifies the drawing in whichthe reference number first appears. Unless otherwise indicated, thedrawings provided throughout the disclosure should not be interpreted asto-scale drawings.

DETAILED DESCRIPTION

As described above, while the extreme temperature and pressure changesmay be instrumental in autoclaving medical and dental devices, thechanges in temperature and pressure may also damage certain medical anddental instruments. For example, some medical or dental instruments mayhave internal cavities. The internal cavity of a medical or dental toolmay contain an air pocket. When the pressure and temperature changes inthe autoclave, the air pocket may apply unexpected pressures to themedical or dental instruments in the autoclave.

The air pocket may be near these internal components. For example, if adental mirror's reflective surface is seated in a housing, and the airpocket may be behind the reflective surface in the housing. That airpocket may be at or near atmospheric pressure before the autoclaveprocess. During the autoclave process, the difference in the airpressure in the autoclave and the air pressure of the pocket may exert aforce on the mirror in the housing. If the air pressure differencebetween the autoclave environment and the air pocket is sufficientlylarge, the resulting force on the mirror may force the mirror from thehousing, damaging the dental mirror.

An autoclave process, and its effects on a medical device will bedescribed in detail with examples. When the medical device enters theautoclave, a pressure of an autoclave environment and the pressure ofthe air pocket are equal (approximately, 1 atmosphere, for example).When the autoclave process begins, the temperature may first rise. Thisheats the medical device raising the pressure of the air pocket. Thus,the stresses on medical device may be from both internal pressure andexpansion. According to disclosed embodiments, the increased pressurefrom the air in the air pocket is reduced by allowing air to exitthrough a valve. As the autoclave process continues, there is a racebetween the rising pressure of the autoclave environment and the risingpressure of the air pocket. By allowing air to exit through the valve,the internal forces due to the pressure difference are controlled. Whenthe autoclave process reaches an equilibrium, temperature is uniform(for example, 134C) and the pressure is uniform or close to uniform (forexample, 2 atmospheres) among the autoclave and the medical device. Notthat the pressure of both the air pocket and the autoclave environmentare equal at this point due to the temperature rise in the autoclave.

As the autoclave process concludes, the autoclave environment pressureand temperature decrease. While the pressure of the autoclaveenvironment decreases, the pressure of the air pocket may decrease moreslowly due to the retained heat. Accordingly, the valve will permit airto exit the air pocket. Eventually, near the end of the cycle, thepressure of the autoclave environment decreases to 1 atmosphere. As themedical device cools, the pressure of the air pocket continues to dropand eventually may drop below the environment pressure. If the valve iscoupled to a plug, this may result in some small effort to remove theplug. According to an embodiment, a valve allows air to escape from theair pocket when air is removed from the autoclave chamber or thepressure difference is high because of the heating of the air inside thecavity. However, the valve also prevents moisture from the steam fromentering the air cavity and possibly damaging electronic componentstherein. Reference will now be made in detail to embodiments of plugsfor medical and dental instruments, examples of which are illustrated inthe accompanying drawings.

As illustrated in FIG. 1, plug 100 is configured to engage with a dentalinstrument 156. Dental instrument 156 may be at least a portion of asmart dental mirror device. For example, dental instrument 156 may havea reflective surface 101 that a health care provider may use to view theinterior of the patient's mouth. Reflective surface 101 may be made ofan optical substrate configured to reflect light, such a glass orsapphire. Reflective surface 101 is also referred to as a viewfindermirror, as it may be used as a viewfinder directing the capture ofdesired images in the patient's mouth.

Dental instrument 156 has a cavity 158 formed in one side of dentalinstrument 156. As will be described below, dental instrument 156 mayhouse electronic components, such as an image sensor, lights, andcontrol circuitry, that may fail if exposed to pressure, moisture, andsteam. And yet, according to embodiments, dental instrument 156 may beautoclavable. As will be also discussed below, cavity 158 may beconfigured to engage with another component, called a streamer, whichhouses electronic components that are not subject to autoclaving.

In some embodiments, dental instrument 156's cavity 158 is fluidlyconnected with internal areas of dental instrument 156. These internalareas are where electronic components are housed. To allow for fluidconnection, a pin hole (not shown) may exist that allows gases, such asair and steam, to transit between cavity 158 and the internal areas.These internal areas also may be where known or expected air pocketsform. For example, it may be known that an air pocket may form behindthe mirror of a dental mirror, where several control circuitry and othercomponents are housed. Thus, a volume behind the mirror may be fluidlyconnected to cavity 158. This fluid connection may be, for example, asmall hole forming a passage for the air pocket, or may be one or morevalves or pumps to control the movement of air from the known orexpected air pocket into cavity 158. A diaphragm may also be included toreduce the moisture flow while still permitting gas flow.

In the absence of this small hole, dental instrument 156 may have an airpocket behind reflective surface 101. When the pressure in the autoclavemachine drops (or the temperature increases), a difference between apressure within the air pocket and in the autoclave chamber may dislodgereflective surface 101. Because the air pocket behind the mirror isfluidly connected to cavity 158, the air in the air pocket can escapefrom the dental instrument 156 through the cavity.

While allowing escape during the pressure drop, the small hole also mayallow steam to enter the device when dental instrument 156 isautoclaved. The steam can cause electronic components within dentalinstrument 156 to fail. To avoid this, in some embodiments, dentalinstrument 156's cavity 158 may be sealed by plug 100. Plug 100 mayserve multiple functions. For example, plug 100 may seal cavity 158 toprevent particles, steam, or other contaminants from entering cavity 158and hence the interior of dental instrument 156. Plug 100 may also actas a one-way valve to permit the release of pressure from inside cavity158 during the autoclave process. Although not shown in FIG. 1, inalternative embodiments, the one way valve in plug 100 may be built intodental instrument 156, avoiding the need for a hole to allow fluidconnection between cavity 158 and the interior of dental instrument 156.

According to some embodiments, plug 100 has housing 102. Housing 102 maybe formed of any number of materials, including, for example, stainlesssteel. Housing 102 may be shaped to fit tightly into a void of cavity158. For example, if the opening to cavity 158 is circular, housing 102may also be circular. Housing may have a proximal end 120 and a distalend 122. Housing 102 has a housing outer surface 104 and a housing innersurface 106. One or more grooves 126 may be formed in housing outersurface 104. Grooves 126 may be shaped to receive gaskets 124 as shownin FIG. 3. Gaskets 124 help to provide an airtight seal for cavity 158.

According to some embodiments, housing 102 may have inner surface 106.Inner surface 106 may be configured to receive additional components, asillustrated in the cross section in FIG. 4. For this purpose, innersurface 106 may have components that mate with additional components.For example, inner surface 106 may have treaded surfaces. In someembodiments, inner surface 106 of housing 102 may have differentsections.

For example, as illustrated in FIG. 4, housing 102 may have a firstsection 108, a second section 110, and a third section 112. Each sectionmay have a different size or shape. For example each of first, second,and third sections may be circular and have a first section diameter114, a second section diameter 116, and a third section diameter 118,respectively. The various sections may be shaped to aid in the placementof different components on the interior of housing 102. For example,first section diameter 114 may be less than second section diameter 116,which may be less than third section diameter 118. In this way, anobject inserted into housing 102 may be funneled to the proper location.Gasket 502 may be positioned to rest at the position where the secondand third sections meet.

As shown, for example, in FIGS. 2 and 3, an end piece 128 may be locatedat the distal end of plug 100. This may be a flat surface protrudingradially from the dental mirror that aids in handling or storing plug100. An end piece void 130 may be formed in end piece 128. End piecevoid 130 may permit plug 100's housing 102 to permit fluid communicationwith the environment, such as the environment of an autoclave and cavity158.

According to some embodiments, plug 100 includes a release plug 132.Release plug 132 may be configured to be coupled to housing 102 byengaging housing inner surface 106. For example, release plug 132 may becoupled to housing inner surface 106 using a threaded connection. Insome embodiments, release plug 132 may be formed as one piece with plug100.

Release plug 132 operates as a one-way valve. Release plug 132 permitshigher pressure air from inside cavity 158 to escape from cavity 158during the autoclave process but prevents air (and steam) fromre-entering cavity 158. Release plug 132 includes a hollow cylindricalbody 134 through which the air may escape. Release plug 132 may have aproximal end 136 and a distal end 138. A piston rod 144 may be insertedin hollow cylindrical body 134. A sealing member 184 may be located atthe distal end of piston rod 144 and may seal hollow cylindrical body134. A spring 146 may be coupled to the proximal end of piston rod 144and may bias piston rod 144 in the proximal direction. An indicator 152may be coupled to the distal end of sealing member 184. Indicator 152may be a visual indicator, for example a different colored segment.

Release plug 132's hollow cylindrical body 134 may also include a firstposition 140 and a second position 142. First position 140 may be distalof second position 142.

FIGS. 6A-6C show a schematic representation of release plug 132'soperation. Each figure shows sealing member 184 coupled to piston rod144. A proximal opening Op is fluidly coupled to cavity 158. A distalopening Od is fluidly coupled (i.e. open) to the environment of theautoclave device. The operation of release plug 132 is best understoodwith reference to the forces acting on sealing member 184 during theautoclave procedure. As previously mentioned spring 146 biases sealingmember 184 in the proximal direction. Thus, spring 146 applies force Fsin the proximal direction. The pressure difference between the pressurein cavity 158 and the environment of the autoclave also applies a forceto sealing member 184. The magnitude and direction of the force isdependent on the difference in the pressure in cavity 158 and theenvironment of the autoclave. The pressure in the autoclave environment,Pa, may result in a force, Fa, on sealing member 184. For example, whenthe pressure Pa in the autoclave is greater than the pressure in thecavity, sealing member 184 may have a resulting force in the proximaldirection. When the pressure in the autoclave is less than the pressurein the cavity, the force on sealing member 184 is in the distaldirection.

The relevant forces on sealing member 184 can thus be summarized asF=(Fp−Fa) −Fs, where (Fp−Fa) is the force from the difference in thepressures (Pp−Pa)*(area of sealing member 184), Pp is the pressure inthe cavity, and Fs is the force of the spring. In FIGS. 6A-6C, forces Faand Fp are shown to represent pressure forces in the differentdirections. The resulting force from the pressure difference could be ineither the proximal or the distal direction, depending on the pressuredifference. Additional forces may also be present but are not shown. Forexample, there may be additional normal forces to the surfaces ofsealing member 184 as it moves in the channel.

Components adjacent to the cavity may be sensitive to forces exerted bythe pressure in the cavity. For example, if a mirror seals the cavity,the mirror may be unable to withstand a force in excess of 0.5 kgf. If,for example, the mirror has an area of 3.14 cm², the pressure in thecavity should not exceed 0.16 Bar above the pressure of the environment(Force (kgf)=Pressure (Bar)*Area (cm²)). This may be considered themaximum permitted pressure difference. To avoid the over pressure, thevalve should release pressure from the cavity before the maximumpermitted pressure difference is reached. If a spring is used as part ofthe valve, for example, the spring force should be calibratedappropriately. For example, if the sealing member has an area of 0.125cm², the spring should be calibrated to provide a force of no more than0.02 kgf when extended to a point to permit gas to exit the cavity. Thisis calculated, for example, by multiplying the maximum permittedpressure difference by the area of the sealing member.

FIG. 6A shows sealing member 184 during the process of the autoclaveprocedure where the pressure in the autoclave drops. At this point, theforces acting on sealing member 184 drive sealing member 184 in thedistal direction because the pressure inside cavity 158 is greater thanthe pressure in the autoclave. Once sealing member 184 is sufficientlydisplaced, air trapped in cavity 158 is allowed to escape into theautoclave. This begins to equalize the pressure between the autoclaveenvironment and cavity 158. As the pressure begins to equalize, sealingmember 184 moves in the proximal direction because the spring forcedominates.

FIG. 6B shows sealing member 184 at a first position 140. At thisposition, cavity 158 remains sealed, but is on the verge of allowingmore air to exit cavity 158. Thus, if pressure continues to drop in theautoclave (or equivalently, raise in the cavity), sealing member 184will move distally from first position 140 to permit more air to exitfrom cavity 158.

FIG. 6C shows sealing member 184 at a second position 142. As previouslymentioned, second position 142 is proximal (i.e. closer to cavity 158when in use) than first position 140. As the pressure rises in theautoclave during the autoclave process, the increased force drivessealing member 184 to second position 142. At the end of the autoclaveprocedure, when the pressure in the autoclave is equal to atmosphericpressure and the temperature dropped to room temperature, the pressurein cavity 158 should be approximately the lowest pressure experiencedduring the autoclave procedure. In some procedures, this is lower thanthe environment pressure. Accordingly, sealing member 184 is held insecond position 142 by the combined force of spring 146 and the higherpressure of the outside environment.

An indicator 152 may be on the distal end of sealing member 184.Indicator 152 may be, for example, a painted feature, sticker,reflector, or other indicator. Indicator 152 may aid the operator inconfirming that the autoclave procedure adequately sterilized themedical device and may also confirm that the medical device is notdamaged.

As previously mentioned, after the autoclave procedure, the pressure incavity 158 should be low compared to the pressure of the surroundingenvironment. Thus, indicator 152 should be mostly obscured because it islocated at second position 142. However, if, after the autoclaveprocedure, indicator 152 is visible (or, in some embodiments,prominently visible), the auto clave procedure may have failed.Alternatively, plug 100 may have failed to adequately seal cavity 158,or the medical instrument coupled to plug 100 may be cracked such thatcavity 158 is in fluid connection with the environment of the autoclavedevice. This may indicate to the operator that the medical devicerequires repair or replacement.

FIG. 7 illustrates a breakout diagram showing assembly of a head portionof a dental mirror. As discussed above, dental instrument 156 includesan internal cavity that includes electronic components. The internalcavity and electronic components are illustrated in diagram 700 in FIG.7.

Assembly of the head component involves four layers of components: layer710, layer 720, layer 730, and layer 740. Layer 710 includes a mirrorhead 704 and a handle 702 connected to each other. Mirror head 704includes reflective surface 101, a pass-through 708, and a pass-through706.

Pass-through 708 allows the pass-through of light or visual informationto allow light or visual information to reach an image sensor 732 (sothat a respective image can be captured). Pass-through 706 allows lightfrom light sources 736 to exit mirror head 704. In some embodiments,pass-throughs 706 and 708 are an opening in reflective surface 101. Insome embodiments, pass-throughs 706 and 708 are a transparent or semi-or partially-transparent area in reflective surface 101. In someembodiments, pass-throughs 706 and 708 include an optical lens.Pass-throughs 706 and 708 is a section of the area of reflective surface101 that becomes transparent or partially transparent when light,possibly of an intensity above some threshold, is present. In someembodiments, pass-throughs 706 and 708 are a section of the area ofreflective surface 101 that becomes transparent or partially transparentwhen electrical current or voltage is present. Pass-throughs 706 and 708can be located at the center of or at the perimeter, or at otherlocations of reflective surface 101.

Mirror head 704 in layer 710 is configured to engage with a backing 744and a gasket 742 in layer 740. Backing 744 includes threads configuredto mate with threads on mirror head 704. Those threads are illustratedin FIG. 8. FIG. 8 illustrates a perspective diagram 800 of a shell for ahead portion of a dental mirror. Diagram 800 shows threads 802 that areconfigured to mate with backing 744. Gasket 742 sits between backing 744and threads 802 to create an airtight seal. In some embodiments, asealant is also added while treading the components together to improvethe sealing characteristics.

Returning to FIG. 7, between layers 710 and 740 are layers 720 and 730.Layer 730 include a printed circuit board (PCB) 734 that rests onbacking 744. PCB 730 has an image sensor 732 and a plurality of lightsources 736 arranged around a perimeter of PCB 734. PCB 734 also hassome control circuitry and a connector 738.

Image sensor 732 captures still or video digital images. In someembodiments, image sensor 732 is an image sensor, or plurality thereof,that includes a pixel array, such as a charged coupled device (CCD), ora complementary metal-oxide-semiconductor (CMOS) sensor, or the like.

The plurality of light sources 736 illuminates objects in the proximityof dental instrument 156. In some embodiments, light sources 736illuminate areas of a person's mouth to improve the image reflected inviewfinder mirror 103 or captured by image sensor 732. In someembodiments, a plurality of light sources 736 are included. In someembodiments, light sources 736 emits light. In some embodiments, lightsources 736 transmit light emitted elsewhere in dental instrument 156.In some embodiments, the intensity of the light emitted or transmittedby light sources 736 can be controlled. In some embodiments, theintensity of illumination by a plurality of light sources 736 isconcurrently controlled. In some embodiments, the intensity of eachlight sources 736 of a plurality of light sources 736 is independentlycontrolled. In some embodiments, a plurality of light sources 736 allemit or transmit the same or similar light wavelengths (or colors). Insome embodiments, different wavelengths (or colors) may be emitted ortransmitted by a plurality of light sources 736. In some embodiments,each light source 736 is a led emitting diode (LED). In someembodiments, each light source 736 is a light pipe, such as an opticalfiber cable or the like. In some embodiments, each light source 736 is amonochromatic light (a laser).

Connector 738 receives signals to control the plurality of light sources736.

Layer 720 rests on top of layer 730 and includes a light diffuser 726,mirror support 724 and lens protector 722.

Light diffuser 726 scatters light to soften light emitted from lightsources 736. Light diffuser 726 may include a translucent material suchas ground glass, teflon, opal glass, or greyed glass.

Mirror support 724 provides structural support for reflective surface101. Adhesive may be applied between mirror support 724 and reflectivesurface 101. Mirror support 724 may stiffen reflective surface 101 andmake reflective surface 101 more resistant to fracture.

Lens protector 722 is an opaque construct made out of silicone or othermaterials that can sustain temperatures of an autoclave. Lens protector722 allows light from outside that is to be directed towards thepass-through 708 to enter image sensor 732. Lens protector 722 operatesto block “light pollution.” This reduces the light noise that may bewrongly reflected to the image sensor 732. Lens protector 722 may alsoinclude a lens, a transmissive optical device that focuses a light bymeans of refraction to form an image for detection by image sensor 732.The lens may be a simple lens or compound lens. It may be made of atransparent material such as glass or plastic.

As mentioned above, dental instrument 156 may be at least part of asmart dental mirror. Dental instrument 156 may be autoclavable or mayinclude components of the smart dental mirror that are autoclavable.Components of the smart dental mirror that are not autoclavable may beincluded in a separate piece, which may be called a streamer portion.Because this streamer portion is not to be autoclaved, it may bepositioned on the smart dental mirror such that it does not make contactwith the patient's mouth when used by the healthcare provider.

FIG. 9 illustrates a streamer 900 of a dental mirror. Streamer 900includes a connector 906, a shell 902, and a shell 904. Connector 906 isconfigured to electrically and communicatively connect to dentalinstrument 156. In some embodiments, Shell 902 is shaped to be insertedinto cavity 158 of dental instrument 156. Shell 904 may enclose awireless antenna and may be made of materials that are permeable toelectromagnetic signals.

FIG. 10 includes a diagram 1000 that illustrates the streamer portionwith an outer shell removed. Diagram 1000 illustrates a tray 1002 thatcontains a PCB 1004. As discussed below, PCB 1009 includes a powersubsystem 1006, a processor and memory. It also includes a wirelessantenna and a connector to dental instrument 156 or a power charger or abase station.

FIG. 11 illustrates a block diagram of a smart mirror device 1100. Asdiscussed above, smart mirror device 1100 has two separable components,dental instrument 156 (the head piece for insertion into the oralcavity) and streamer 900, and dental instrument 156 includes imagesensor 732, light source(s) 736, and a connector 738.

It may be appreciated for those skilled in the art that a plurality ofsignal lines or buses 1117 may exist, thus different components may belinked by different signal lines or buses 1117, and that the signallines or buses 1117 depicted in the schematic diagram may represent aplurality of such.

As discussed above for FIG. 1, viewfinder mirror 103 is a mirror, thushaving a reflective area. The reflection from viewfinder mirror 103provides visual guidance to a user about the objects that may beincluded in images captured by image sensor 732. As mentioned above,viewfinder mirror 103 may be round. In some embodiments, viewfindermirror 103 is planar. In some embodiments, viewfinder mirror 103 iscurved, concave, or convex. In some embodiments, viewfinder mirror 103has a spherical shape. In some embodiments, viewfinder mirror 103 has arectangular shape. It can be appreciated by those skilled in the artthat smart mirror device 1100 can be embodied with different shapes ofviewfinder mirror 103 and/or a plurality of viewfinder mirror 103without departing from the spirit of this invention.

Connector 738 of dental instrument 156 connects (physically and/orelectronically) to connector 906 of streamer 900. Connector 906 may be aUSB terminal. Image sensor 732 and light source 736 receive electricalpower from streamer 900 through connector 738. In addition, control andsignaling is passed to and from streamer 900 and light source 736through connector 738. For example, image sensor 732 may transmit imagescaptured via bus 1117 to connector 738, which transmits images tostreamer 900. Similarly, connector 738 may receive and pass alongcontrol information indicating when and whether to activate image sensor732. For light sources 736, connector 738 may receive commands whichcause light sources 736 to activate and determine when and how toactivate them. Connector 738 is adapted to connect to a connector 906 instreamer 900.

Turning to streamer 900, streamer 900 includes an orientation measuringdevice 1112, a user interface 1124, a processor 1123, a base stationconnector 1158, connector 906, communication subsystem 1129, powersubsystem 1121, and a memory 1130.

Base station connector 1158 enables streamer 900, which may or may notbe attached to dental instrument 156, to dock with a base station. Thedocking may occur through a physical connection which holds streamer 900at a predefined orientation. In addition, the docking may occur througha USB or near field communication connection or the like. When dockingwith the base station, streamer 900 may receive electrical power throughbase station connector 1158, which may be used to charge power subsystem1006. In addition, streamer 900 may receive control and signalinginformation through base station connector 1158. For example, basestation connector 1158 may receive information needed to configure awireless communication connection between streamer 900 and the basestation. Base station connector 1158 may provide the wirelessconfiguration information (such as a service set identifier andpassword) to communication subsystem 1129, as is discussed below. And,when docked to a base station, base station connector 1158 may signalorientation measuring device 1112 or software in memory 1130 tocalibrate. In some embodiments, connector 906 may integrated into basestation connector 1158.

Power subsystem 1006 stores power for smart mirror device 1100 andprovides power to the other components of smart mirror device 1100.Power subsystem 1121 may include batteries, such as AAAA batteries, or acapacitor.

Orientation measuring device 1112 measures an orientation (includingx,y,z, position and yaw, pitch, roll direction) of viewfinder mirror 103or generates data that enables it to calculate an orientation ofviewfinder mirror 103. In some embodiments, orientation measuring device1112 is an accelerometer. An example of an accelerometer is MMA8453Qavailable from NXP Semiconductors N.V. of Eindhoven, Netherlands. Insome embodiments, orientation measuring device 1112 is a gyroscope. Anexample of an orientation measuring device 1112 is FXAS21002C alsoavailable from NXP Semiconductors N.V. The gyroscope could also be acompound device such as a TDK invensense.

User interface 1124 includes an audio input 1125, audio output 1126, andinput/output controls 1127. Audio input 1125 captures audialinformation. In some embodiments, audio input 1125 includes amicrophone. In some embodiments, audio input 1125 captures human voice,for example, to enable a healthcare provider to dictate observations fora patient's medical record. Streamer 900 includes an audio output 1126,which emits sounds. In some embodiments, audio output 1126 includes oneor more speakers or buzzers. In some embodiments, audio output 1126includes headphone jacks and/or headphones.

Input/output controls 1127 can include buttons, lights, knobs,capacitive sensors, actuators for haptic feedback or the like for a userto control and/or receive feedback relating to processes in smart mirrordevice 1100, for example, to initiate audio recording or imagecapturing, or set an intensity of illumination.

Communication subsystem 1129 allows streamer 900 to connect to one ormore remote computational devices, including, for example, to a basestation, or to a general purpose computational device such as personalcomputer, a smart phone, a tablet or similar, or a specializedcomputational device such as to another smart mirror device or remotespeakers or the like. In some embodiments, communication subsystem 1129is adapted to connect to a wireless network, including, but not limitedto, WiFi and/or Bluetooth. In some embodiments, communication subsystem1129 is adapted to attach to a wired network, including, but not limitedto, Ethernet, USB or thunderbolt.

In an embodiment, the smart mirror device may be shipped with a stickerwith a visual code, such as a QR code, printed thereon. A smart phone ortablet computing device can scan the QR code and to determine asSSID/Password to connect to a WiFi network hosted from communicationsubsystem 1129. In this way, the tablet computing device can communicatewith the smart mirror device and receive video captured from the smartmirror device.

Memory 1130 may include random access memory (RAM) and may also includenonvolatile memory, such as read only memory (ROM) and/or flash memory.Memory 1130 may be embodied as an independent memory component, and mayalso be embedded in another component, such as processor 1123 and/orimage sensor 732, or may be embodied as a combination of independent aswell as embedded, and/or a plurality of memory components. Memory 1130is adapted to include software modules (a module is a set ofinstructions). In particular, memory 1130 includes a streamer module1153, identification module 1154, illumination controller module 1150,image control module 1151, and orientation calculator module 1168.

Processor 1123 is adapted to run instructions stored in memory 1130.Processor 1123 may be a micro-controller unit (MCU), a digital signalprocessor (DSP) and/or an Image/Video Processing unit or like componentsthat run instructions. An example of an MCU is MSP432P401x availablefrom Texas Instruments Inc. of Dallas, Tex. An example of a DSP is C5000available from Texas Instruments Inc. of Dallas, Tex. An example of animage/video processor is OMAP3525 also available from Texas InstrumentsInc. of Dallas, Tex. Another example of the processor is the FPGA, suchas the one available from Xilinx. One or more processor 1123 may bepresent. Processor 1123 may be an independent component, it may also beembedded in another component, such as in image sensor 732, orientationmeasuring device 1112, or any combination thereof. Each subcomponent mayalso have internal memory devices.

Illumination controller module 1150 controls the operation of lightsource 736. In some embodiments, illumination controller module 1150sets the intensity of illumination of light source 736. In someembodiments, illumination controller module 1150 receives a user requestto increase or reduce illumination. In some embodiments, illuminationcontroller module 1150 receives a user request to turn on or off some orall of light source 736. In some embodiments, illumination controllermodule 1150 receives requests from other software modules to increaseand/or decrease illumination of one or more of light source 736. In someembodiments, user input as well as said requests are used to determinean intensity of illumination.

Orientation calculator module 1168 reads data from orientation measuringdevice 1112. Orientation calculator module 1168 may for exampleintegrate data from a gyroscope and accelerometer to determine alocation (in, for example, x,y,z coordinates) and a direction (forexample, yaw, pitch, and roll). Because orientation calculator module1168 uses integration to determine the location and direction of smartmirror device 1100, errors from the gyroscope and the accelerometer canaccumulate over time. However, as described above, base stationconnector 1158 may dock with the base station in such a way to positionstreamer 900 at a known angle. When base station connector 1158 isdocked with the base station, base station connector 1158 may signalorientation calculator module 1168 to calibrate. To calibrate,orientation calculator module 1168 may set the x, y, z, and yaw, pitch,and roll values to fixed values, such as the value zero. Thus, whenstreamer 900 is moved around, the coordinate and direction valuesorientation calculator module 1168 determines values which may berelative to the coordinate and direction values set at the base station.

Image control module 1151 controls the capture of images and video, andaffects the output image quality. In some embodiments, image controlmodule 1151 controls the intensity of illumination, for example, byrequests to illumination controller module 1150, for example, to improvethe illumination conditions for a better image capture quality. In someembodiments, image control module 1151 processes a set oftime-successive images to create a single output image which has animproved visual quality, for example, but not limited to by selectingone image out of the set, or by combining portions of images, eachportion from an image in the set. In some embodiments, values indicatingthe acceleration of image sensor 732 when an image was captured are usedto improve the quality of an output image, for example, but not limitedto, selecting images with least acceleration or interpolating amongportions of two or more images of different acceleration. In someembodiments, image control module 1151 controls the aperture and/orfocal point of a lens. In some embodiments, image control module 1151triggers the capture of a sequence of images each with a differentillumination. In some embodiments, image control module 1151 triggersthe capture of a sequence of images each with a possibly different groupof one or more of light sources 736 set to illuminate, while the otherone or more of light source 736 are set to not illuminate. In someembodiments, image control module 1151 rotates an image, for examplebased on a rotation value generated by orientation calculator module1168.

Identification module 1154 identifies smart mirror device 1100 to aremote computational device. In some embodiments, identification module1154 implements an authentication handshake protocol in which theidentification occurs over a network session. In some embodiments,identification module 1154 couples an identification to data prior tothe data being transferred to a remote computational device. Theidentification may include a globally unique ID for streamer 900. It mayalso be timestamped and digitally signed.

Streamer module 1153 prepares and/or streams data to a remotecomputational device. The data can include video collected from imagesensor 732, smart mirror device 1100's orientation and locationcollected from orientation calculator module 1168, audio input collectedfrom audio input 1125, any data collected from input/output controls1127, power related data collected from power subsystem 1006 and thespecification of how light source 736 is illuminated from illuminationcontroller module 1150. Streamer module 1153 may associate datacollected from these various sources with each other. To associate datacollected from different sources, streamer module 1153 may attach atimestamp. For example, each frame in video image sensor 732 may includea timestamp which is collected. Similarly, the orientation, audio,power, and input control information may have a timestamp indicatingwhen that information was collected, and the illumination informationmay have a timestamp indicating when light source 736 was illuminated inthe manner specified.

In some embodiments, streamer module 1153 formats images, video, audioand other data in a format for streaming to an application executing ona remote computational device via communication subsystem 1129. In someembodiments, streamer module 1153 formats images, video, audio and otherdata in a format suitable for streaming to an Internet browser, forexample, but not limited to, HTTP streaming, HTML, HTML5, RTSP, WebRTC.In some embodiments, streamer module 1153 formats images, video, audioand other data with compression formats and/or format containers suchas, but not limited to, JPG, JPG 2000, MPEG-4, H.264, H.265, AAC, PCM,G.711, G.726, and the like. In some embodiments a proprietary format isused, the invention is not so limited.

Estimation terms, such as “approximate,” “approximately,” “about,” andthe like may be used herein to indicate the value of a given quantitythat may vary based on a particular technology and/or certainparameter(s). For example, the estimation term may modify amounts,sizes, formulations, parameters, and other quantities andcharacteristics, and need not be exact, but may be approximate and/orlarger or smaller, as desired, reflecting tolerances, conversionfactors, rounding off, measurement error and the like, and other factorsknown to those of skill in the art. Such estimation terms may indicate avalue of a given quantity that varies within, for example, 0-10% of thevalue (e.g., ±0.5%, ±5%, or ±10% of the value).

Directional and spatially relative terms, such as “inner,” “outer,”“proximal,” “distal” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The directionaland spatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. The apparatus may be otherwiseoriented (rotated 90 degrees or at other orientations) and thedirectional and spatially relative descriptors used herein may likewisebe interpreted accordingly.

As used herein, the singular forms “a,” “an” and “the” include pluralreferents unless the context clearly dictates otherwise. Thus, forexample, reference to “a” component includes aspects having two or moresuch components, unless the context clearly indicates otherwise.

It is to be understood that the phraseology or terminology herein is forthe purpose of description and not of limitation such that theterminology or phraseology of the present specification is to beinterpreted by those skilled in relevant art(s) in light of theteachings herein.

The embodiment(s) described, and references in the specification to “oneembodiment,” “an embodiment,” “an example embodiment” and the likeindicate that the embodiment(s) described may include a particularfeature, structure, or characteristic, but every embodiment may notnecessarily include the particular feature, structure, orcharacteristic. Moreover, such phrases are not necessarily referring tothe same embodiment. Further, when a particular feature, structure, orcharacteristic is described in connection with an embodiment, it isunderstood that it is within the knowledge of one skilled in the art toeffect such feature, structure, or characteristic in connection withother embodiments whether or not explicitly described.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the embodiments describedherein without departing from the spirit and scope of the claimedsubject matter. Thus it is intended that the specification cover themodifications and variations of the various embodiments described hereinprovided such modification and variations come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. A medical device comprising: a cavity; a channelformed in the medical device between the cavity and an autoclaveenvironment outside the cavity, a proximal end of the channel opening tothe cavity and a distal end of the channel opening to the autoclaveenvironment; and a valve; wherein the valve permits gas to flow from thecavity when a pressure inside the cavity is greater than a pressure inthe autoclave environment outside the cavity, and wherein the valveprevents gas from flowing into the cavity when the pressure in theautoclave environment outside the cavity is greater than the pressureinside the cavity.
 2. The medical device of claim 1, wherein the valvecomprises a piston rod, the piston rod extending into the channel, and asealing member connected to the piston rod.
 3. The medical device ofclaim 2, wherein the valve further comprises a spring around the pistonrod, the spring applying a spring force to the piston rod in a proximaldirection.
 4. The medical device of claim 1, further comprising aprinted circuit board, the printed circuit board disposed in the cavity.5. The medical device of claim 4, further comprising an image sensor,the image sensor operatively coupled to the printed circuit board anddisposed within the cavity.
 6. The medical device of claim 4, furthercomprising a light source, the light source operatively coupled to theprinted circuit board and disposed within the cavity.
 7. The medicaldevice of claim 5, further comprising a connector, the connectoroperatively coupled to the image sensor and configured to receive astreamer, wherein the streamer is not autoclavable.
 8. The medicaldevice of claim 1, further comprising an indicator, the indicatorconfigured to indicate a pressure difference between a pressure in anenvironment and the pressure in the cavity.
 9. The medical device ofclaim 8, wherein the indicator is coupled to a sealing member.
 10. Themedical device of claim 8, wherein the indicator indicates the pressuredifference between the environment pressure and the pressure in thecavity by being located at one of a first and a second position.
 11. Themedical device of claim 1, wherein the medical device is an intra-oralmirror.
 12. A plug for use with a dental instrument in an autoclave, theplug comprising: a hollow housing having a distal and a proximal end,the proximal end configured to engage a cavity of the dental instrument;and a valve, wherein the valve permits gas to flow from the cavity ofthe dental instrument when a pressure outside the cavity decreases, andwherein the valve prevents gas from flowing into the cavity of thedental instrument when the outside pressure increases.
 13. The plug ofclaim 12, wherein the valve comprises a sealing member coupled to apiston rod, the piston rod biased in the proximal direction by a spring.14. The plug of claim 12, further comprising an indicator, the indicatorconfigured to indicate a pressure difference between the outsidepressure and a pressure in the cavity.
 15. The plug of claim 14, whereinthe indicator is coupled to the sealing member.
 16. The plug of claim14, wherein the indicator indicates the pressure difference between theoutside pressure and the pressure in the cavity by being located at oneof a first and a second position.
 17. A plug comprising: a hollowcylindrical housing having an outer surface, an inner surface, aproximal end, and a distal end; a gasket positioned in a groove formedon the outer surface of the housing; an end piece coupled to the distalend of the housing, the end piece having a void aligned with the hollowportion of the housing; and a release plug mated with the inner surfaceof the hollow cylinder, the release plug comprising: a hollowcylindrical body, having a proximal end, a distal end, a first locationand a second location, the first location distal to the second location;a piston rod located in the hollow cylindrical body and moveabletherein; a spring around the piston rod, the spring applying a springforce to the piston rod in the proximal direction; and a sealing memberconnected to the distal end of the piston rod, wherein the sealingmember permits gas to flow from the cavity when a pressure inside thecavity is greater than a pressure in the environment outside the cavity,and wherein the sealing member prevents gas from flowing into the cavitywhen the pressure in the environment outside the cavity is greater thanthe pressure inside the cavity.
 18. The plug of claim 17, where in thehollow portion of the housing comprises a first section, a secondsection, and a third section, each of the sections having differentdiameters.
 19. The plug of claim 18, wherein the diameter of the thirdsection is greater than the diameter of the second section, and thediameter of the second section is greater than the diameter of the firstsection.
 20. The plug of claim 19, wherein the first section is proximalto the second section, and the second section is proximal to the thirdsection.
 21. The plug of claim 17, further comprising a second gasketpositioned in a second groove formed on the outer surface of thehousing.
 22. The plug of claim 17, wherein the release plug furthercomprises a release gasket, the release gasket sealing the release plugin the hollow portion of the housing.
 23. The plug of claim 17, furthercomprising an indicator located on the distal end of the sealing member.24. The plug of claim 17, wherein, when a distal pressure is greaterthan a proximal pressure, the sealing member is proximally displaced.25. The plug of claim 17, wherein the release plug is mated with thehousing by a threaded connection.
 26. A medical device comprising: acavity; a channel having a sealing member, the channel formed in themedical device between the cavity and an environment outside the cavity;wherein the sealing member permits gas to flow from the cavity when apressure inside the cavity is greater than a pressure in the environmentoutside the cavity, and wherein the sealing member prevents gas fromflowing into the cavity when the pressure in the environment outside thecavity is greater than the pressure inside the cavity.
 27. The medicaldevice of claim 26, wherein the sealing member comprise a one-way valve.28. The medical device of claim 26, wherein the medical device is anintra-oral mirror.